Outdoor display screens not only require a high level of brightness but also require that a difference in viewing angle between three-primary-color LEDs be within a certain range. However, the technique of adding an optical lens to a three-primary-color light-emitting display device to enhance brightness results in an increased difference in viewing angle. Therefore, in existing structures, the provision of using an optical lens is not suitable.
In view of the above disadvantages, after extensive research in conjunction with theoretical knowledge, the inventor provides the present invention which is reasonably designed and effectively addresses the above disadvantages.